1. Field of the Invention
The present invention relates to a fuel tank system for allowing fuel overflowing from a fuel tank of a vehicle to escape to outside the vehicle. More particularly, the present invention concerns a fuel tank system operative when fuel is supplied excessively to a vehicle tank this, occurrence being hereinafter referred to as "during overfueling" owing to a malfunctioning of an automatic shutoff mechanism of a fuel nozzle or for other reason.
2. Description of the Prior Art
Generally, a fuel nozzle is provided with an automatic shutoff mechanism. The automatic shutoff mechanism prevents fuel from being supplied excessively to the tank.
However, there are cases where the automatic shutoff mechanism fails to operate properly. For this reason, there arises the need for the pump operator to constantly monitor the situation of fueling. As a result, the operation of supplying fuel into the tank has been troublesome.
For instance, if the operator neglects the monitoring, the fuel can overflow from a fuel charging port with the fuel nozzle inserted therein, running down an outer panel of a body. As a result, the painting of the outer panel becomes discolored.
In addition, at the fuel charging port with a fuel recovery valve attached to its inner peripheral surface, it is impossible for the operator to visually ascertain the internal situation through that fuel charging port (refer to U.S. Pat. No. 4,702,386, Japanese Utility-Model Application Laid-Open No. 145922/1975, etc.). For this reason, in the structure in which the fuel recovery valve is provided, the aforementioned problem is liable to occur when the automatic shutoff mechanism of the fuel nozzle has failed.